With the greater variety of components used on printed circuit boards (PCBs), smaller passive components and larger ICs with finer ball pitch dimensions, the demands on high quality solder joints to aid PCB assembly (PCBA) fabrication and rework have increased. Faulty solder joint has cost companies billions of dollars over the years. Many processes have been developed to reduce failure rate for wave solder systems. However, for point to point handheld soldering and rework applications, companies are relying on operators' skills to produce good solder joints with quality electrical connections. Regardless of how much training is provided to the operators of the soldering iron, without guidance during a soldering activity, the operators may make and repeat mistakes due to the fact that there are many factors that impact heat transfer by the soldering iron for forming a solder joint with good electrical connection. These factors include solder tip temperature, geometry of the solder tip, oxidation of the solder, human behavior, and the like.
Moreover, automatic (e.g., robotic) soldering is currently strictly an open-loop time based event, where a robot moves to the specific joint, the solder tip is automatically placed on the joint, solder is automatically applied, and a prescribed time later (determined by a specific software for the robot), the solder tip is automatically removed from the joint. This process is repeated until the robot's program is complete. This open-loop time based event can be significantly improved by using the various embodiments of connection validation (CV) technology disclosed herein, with a real-time feedback of the solder quality.